Pick-tip attachment fob telephone receivers



Jan. 19,` 1932. w. ocHsE 1,842,190

PICK-UP ATTACHMENT FOR TELEPHONE RECEIVEHS Filed ook. 1, 1928 Patented Jan. 19, 1932 PATENT OFFICE WILLIAM OCHSE, 0F SAN ANTONIO, TEXAS PICK-UP ATTACHMENT FOR TELEPHONE RECEIVERS Application illed October 1, 1928. Serial No. 309,492.

This invention relates generally to telephony. More particularly, my invention relates to aI Certain new and useful improvement in Vpick-up attachments for telephone receivers and has for its object the provision of a simple, inexpensive, conveniently installed device for efliciently amplifying and audibly reproducing the pulsations of the receiver.

With the above object in view, my invention resides in the provision of a device for .coupling a telephone-receiver with a remote or separate reproducing device, the couplingdevice including'means inductively responsive to variations in the field of the electromagnet, of the receiver, in association with a circuit, or so-called hook-up, for transmitting said variations to the reproducing device; in the provision of a device of the character stated associated with a sound reproducing device,the coupling-device including means for amplifying and transmitting to the reproducing device the current changes in an inductance -or so-called pick-up coil responsive-to variations in the vintensity of the field of the electromagnet of the telephone receiver; in the provision of a device of this kind adapted for association with the usual diaphragm of the telephone receiver for varyingthe intensity of the magnetic field of a pick-up inductance lin response to flexural movement ofthe diaphragm; in the provision of a device of the type stated having means for matching the polarity of a picky up coil with the field of the electromagnet of the telephone receiver; in the provision of a device of the type Vstated having means for varying the coupling of a pick-up coil with the electromagnet of the telephone-receiver and with'the diaphragm thereof; and in the novel features of form, construction, arrangement,and combination of parts hereinafter ydescribed and pointed out in the claims.

In the accompanying drawings,

Figure 1 is a diagrammatic illustration of my invention associated with a thermionic amplifying and transmitting device deliverzing its output to a sound reproducer, in connection with the electromagnet of the telephone receiver and a source of energy and potential;

Figure 2 is a longitudinal sectional view through the pick-up attachment as detachably mounted on a telephone receiver, portions of the latter being'broken away; and

Figure 3 is a sectional View along the line 3--3, Figure 2.

Referring now more in detail and by reference characters to the drawings, which illustrate a preferred embodiment of the invention, my present device, generally described, includes a shell or body A which is adapted for attachment to the standard telephone-receiver B and which carries a rotatin contour, has a bore l longitudinally axially i aligned with the receiver and counter-bored, as at 2, the Wall of the counterbore 2 being threaded, as at 3, for attaching co-operation with the usual threaded end 4 of the telephone receiver B that is exposed after removal of the standard ear-piece (not shown) commonly threaded to the receiver. As is Well known to those skilled in the art, the removal of the ear-piece permits the removal or replacement of the metallic diaphragm 5 of the receiver B, and this diaphragm may be thus removed from the receiver B prior to threading the shell A thereon, at the option of the person using the device. If so removed, the pick-up coil E is responsive only 9' to telephonic alternations in the telephonereceiver B, but if the diaphragm 5 is not removed, the flexural vibrations thereof also effect the pick-up coil E.

The guide-member C,Which is also preferably tubular in contour and which, as stated, is rotatably mounted in the bore 1 of the shell A, is prevented from longitudinal or axial movement in the bore by a key 6 passed through the shell A for sliding` cooperation with a circumferential or annular groove 7 provided suitably in the guide C. That end ofthe guide-member C that `is away from the receiver B is closed by an end wall 8 laterally extended beyond the shell A preferably for sliding contact with the adjacent end thereof and provided with a knurled edge 9 for rotational manual manipulation of theguide C, as presently appearing.

Longitudinally or axially shiftable in a guideway or bore 10 of the guide-member C, is thepick-up coil or magnet supporting carrier D, whichis preferably cup-shaped or chambered, and which is held from rotation relatively to the guide-member C by a longitudinal key 11 mounted in the bore 10 for sliding co-operation with a longitudinal keyway or slot 12 in the carrier D.- The open end ofthe chamber 13 of the ycup-shaped carrier D faces toward the electromagnet lilof the telephone-receiver B whenv the device is mounted thereon, the other or. outer end of the carrier D being closed by an end wall 15 facing the end wall 8 of the guide-member C@ Mounted in the chamber 13 Aon theinner face of the end wall 15 in symmetrical relation with respect to the axis of the yelectromagnet 14 of the telephone receiver B, is the preferably iron-core pick-up coil or inductance E, which preferably comprises a pair of windings 16 each having an iron core or pole piece V17, the pole pieces'being mechanically and magnetically connected by an iron yoke 18`attached to the end wall 15, the inductance E thus preferably forming a socalled horse-slioe magnet facing towards the electromagnet 14 and the diaphragm 5, if used. y

Centrally threaded through the end 'wall 8 of the guide vmember C, is an adjusting Screw 19 having its inner end rotatably retained by a key 20 disposed through the end wall 15 of the carrier D for. sliding co-operation with an annular groove 21 in the screw 19, the outer or projecting endl of the screw 19 being provided with a preferably knurled head 22 for manual manipulation 'of the screw 19 to move the carrier D and its supported pick-up coil E towards or away from the diaphragm 5 or the electromagnet 14 of the 'telephone-receiver B.

The structure thus described is preferably constructed of non-magnetic materials, as vulcanizedrubber, bakelite, brass, and the like, as may be suitable tothe severalparts, eX- cept, of course, those parts carrying electric or magnetic circuits, as the pole pieces 17, windings 16, and yoke 18.

The respective terminals 23, 24, of the pickup inductance E are preferably passed through the end wall 15 of the carrier D and thence preferably through the end wall 8 of the guide-member C for electrical connection with a suitable source of potential F, and also, preferably, through the amplifying and transmitting device G to the sound reproducer H.

One arrangement of such connection is diagrannnatically illustrated in the drawings, one terminal, as 23, ofthe pick-up coil E being connected to the grid of a thermionic device orthree-electrode tube 25, the plate thereof being connected to the primary of a. socalled audio-transformer 26 and thencev by the lead 2"? to the source ofl energy and potential F, such as a common B battery 28. The secondary of thetransformer 26 is connected at one end to the grid of a-second thermionic tube 29, and at the other end 'tlirouoh the leadv 30 to the source -of potential F preferably through the usual C battery 31. 'lhe plate of the tube 29 is connected through the sound reproducer or so-called loud-speaker to the B battery 28 preferably by the lead 27. The usual negative filament returns are indicated by the lead 32 to complete the potential and energy circuits ofthe amplilier, the other connections of the filament circuits not being indicated on the drawings, being of the 4usual. form well known to those skilled in the art. j

lt will be readily understoodgthat variations, particularly at audio frequency, in the intensity of the magnetic flux surrounding the pick-up inductance E will vary the grid voltagel of the valve orltube 25, with corresponding amplification of such variations through the amplifier and transmitting de- .vice Gr in accordance with the characteristics of the tubes employed, the speaker H reproducing vsaid variations in the form of audible sound. j

By rotating the guide-member C in the shell A, the polarity of the pick-up coil E vmay be Vadj usted or brought into proper Aphase relation suitably to the field of the electromagnet 14 of the telephone receiver B to which the rdevice is detachably mounted, and by manipulating the screw 19 the pick-up inductance E may be moved towards or away from the electromagnet 14 and thus adjusted for so-called tight or loose coupling therewith, or for adjustment ofthe air gap between the pole pieces 17 and the diaphragm 5, if the latter is used.

Thus it will be seen that my invention provides a device or pick-up attachment for coupling` a telephone receiver with a reproducing device, the latter being preferably connected'through a thermionic amplifying device. The reproducing device may `take the form of a so-called loud-speaker, but it also may take the form of a so-called dictaphone or other sound recording device. My invention is particularly useful in reproducing with so-called loud-speaker volume a telephonic conversation and for other like objects of great practical utility and value.

It will be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the device may be made and substituted for those herein shown and described without departing from the nature and principle of the invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. In a pick-up attachment for telephone receivers, a pair of series-connected magnetically responsive windings adapted for inductive coupling with the electromagnet of a telephone-receiver, means for adjusting the coupling of the windings with said electromagnet, means for adjusting the polarity of said windings with respect to said electromagnet, means for supporting said windings on the receiver, and means connecting said windings with a source of potential.

2. In a pick-up attachment for telephone receivers, a pair of series connected electrical windings adapted for disposition in the iield of the electromagnet of a telephone-receiver, means for varying the coupling of said windings with said electromagnet, means for adjusting the polarity of said windings with respect to said electromagnet, means .detachably supporting said windings on the receiver, and means for connecting said windings with a source of potential.

3. In a piclcup attachment for telephone receivers, an inductance including a pair of electrical windings having its magnetic iield adapted for association with the diaphragm of a telephone-receiver, means for varying the air-gap between the windings of said inductance and said diaphragm, means for rotating said windings for adjusting the polarity ot' said inductance with respect to the electromagnet of the receiver, and means for connecting said inductance with a source of potential.

4. In a pickup attachment for telephone receivers, a body member adapted for mounting on a telephone receiver, said member liaving a bore longitudinally axially aligned with the receiver, a tubular guide member mounted ifor rotation in said bore, means provided on said guide-member for rotational manipulation thereof, a carrier shiftably disposed in said guide-member, means for shifting said carrier in the guide-member, an inductance mounted on the carrier for movement in inductive relation-ship with the electromagnet of the receiver, and means for connecting said inductance with a source of potential.

5. In a pick-up attachment for telephone receivers, a pair ot series-connected magnetically responsive windings adapted for inductive coupling with the electro-magnet of a telephone receiver, means for rotarily shifting said windings relatively to the magnet for varying the phase relationship of said windings with respect to the magnet, means for movably supporting said windings on the receiver, and means for connecting said windings with a source of potential.

6. In a pick-up attachment for telephone receivers, in combination with a sound reproducing device, an inductance movably disposed in the iicld of the electro-magnet of a telephone receiver, means for rotatably shifting said indnctance relatively to the magnet for adjusting the polarity of the inductance suitably to the iield of the magnet, and means for electrically connecting said inductance with said sound reproducing device.

7. In a pick-up attachment for telephone receiver, in combination with a sound reproducing device, an inductance, means for movably supporting the inductance in the field of the electro-magnet of a telephone receiver, means tor rotatably shitting said inductance reiatively to the magnet for adjusting the polarity thereof suitably to the lield of the magnet, means for amplifying the potential changes in said inductance, and means for transmitting said potential changes to said sound reproducing device.

In witness whereof, I have signed my name to this speciiication.

WILLIAM OCI-ISE. 

